Environment, Development and Sustainability

Jinliang Huang, Jie Lin, and Zhenshun Tu

“Geographic information system (GIS), remote sensing (RS), gradient analysis, and landscape pattern metrics were coupled to quantitatively characterize the spatiotemporal change of land use and landscape pattern over the period 1988–2007 in a coastal gulf region, southeast China. The results obtained show an increase in cropland, buildup land, and aquiculture area and decrease in orchard, woodland, and beach area during 1988–2007. Landscape fragmented processes were strengthened and landscape pattern structure became more complicated in the last two decades in Luoyuan gulf region. The dynamics intensity of landscape pattern is stronger during 2002–2007 than that during 1988–2002. Spatial difference of urban–rural landscape pattern can be detected distinctively in two transects in terms of landscape metrics. Urbanization processes and the policy developed to transfer seawater into buildup land are two driving forces leading to the spatiotemporal change of landscape pattern in Luoyuan gulf region in the last two decades.”

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Arid Land Research and Management

Shoubo Li and Wenzhi Zhao

“Desert oasis wetlands are distributed along the Heihe River, especially in lowland oases along the middle reach of the river, in northwestern China. Landscape maps of the wetlands in 1990, 1995, 2000, and 2006 were compiled based on data collected from Landsat TM and ETM+ images using GIS and analyzed in July 2008. Various landscape indices were calculated using the landscape structure analysis software FRAGSTATS, at both class and landscape levels. The results showed that floodplain wetland is the dominant type of wetlands in the middle reach of the Heihe River, followed by non-forested peatland, then river and reservoir wetland, with the proportion of shrub-dominated wetland low. During these 16 years, the area of wetlands in our study area decreased by 38.4%, or 107.8 km². The major type of wetland lost in the study area was non-forested peatland during the first five years, but floodplain wetland since then. The landscape pattern shows that the fragmentation level is very high, especially in the floodplain wetlands: the patch density increased by 154% during the study period. It is clear that the wetlands along the middle reach of the Heihe River have become increasingly fragmental during the past 16 years.”

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Electronic Journal of Geotechnical Engineering

Omar Al-Kouri, Husaini Omar, Mohammed Abu-Shariah, Ahmad Rodzi Mahmu, and Shattri Mansor

“Nowadays, geographical information system (GIS) and remote sensing are emerging as powerful techniques widely applicable in natural resource management and development virtual models. Recent developments in remote sensing, aerial photography and GIS make it possible to detect changes and devise strategies based on these changes. The study focuses on using aerial photography for the detection of changes and effects of mining on geomorphology using the ArcGIS9 extension, Geostatistical Analyst. In addition, the distinctive surface topography of karst landscapes can be characterized in order to compare them with non-karst landscapes, and to determine geological and/or climatic conditions that are responsible for the observed terrain of Kinta Valley Limestone formation at Perak, Malaysia. Geostatistical analyses of the karstic terrain are used in order to distinguish between karst and non-karst area and karst area to observe the variation from the deterministic sample. In contrast, if the range is less, that means the average distance between two points that are similar in height is less and therefore there is more variation in the area. The average range for karst area is 435, while the average range for non-karst area is 690 meters. The difference between the major range and minor range which indicates the degree of anisotropy is more for the karst area and this is an indicator of more variation in spatial structure and autocorrelation of the karst elevation.”

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International Journal of Digital Earth

Maged Marghany; Arthur P. Cracknell; and Mazlan Hashim

“Multi-frequency C and L bands in the TOPSAR data have been utilized to reconstruct three-dimensional (3-D) bathymetry pattern. The main objective of this study is to utilize fuzzy arithmetic to reduce the errors arising from speckle in synthetic aperture radar (SAR) data when constructing ocean bathymetry from polarized SAR data. In doing so, two 3-D surface models, the Volterra algorithm and a fuzzy B-spline (FBS) algorithm, which construct a global topological structure between the data points, were used to support an approximation to the real surface. Volterra algorithm was used to express the non-linearity of TOPSAR data intensity gradient based on the action balance equation (ABC). In this context, a first-order kernel of Volterra algorithm was used to express ABC equation. The inverse of Volterra algorithm then performed to simulate 2-D current velocities from C_VV and L_HH band. Furthermore, the 2-D continuity equation then used to estimate the water depth. In order to reconstruct 3-D bathymetry pattern, the FBS has been performed to water depth information which was estimated from 2-D continuity equation. The best reconstruction of coastal bathymetry of the test site in Kuala Terengganu, Malaysia, was obtained with polarized L and C bands SAR acquired with HH and VV polarizations, respectively. With 10 m spatial resolution of TOPSAR data, bias of -0.004 m, the standard error mean of 0.023 m, r ² value of 0.95, and 90% confidence intervals in depth determination was obtained with L_HH band.”

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15-20 June, 2010, Nessebar, Bulgaria

Borislav Marinov and Margarita Mondeshka

“The comparative study of land cover and soil status are provided using space images with middle resolution. The Landsat TM+ and SPOT 5 images are included in analysis. The unsupervised and supervised classifications are applied for determination of different types of land cover. The terrain investigations are made by taking and analysing the soil samples for typical soil types presenting in the area of investigation. The analysed images are taken at different time moments in autumn and spring seasons to avoid the influence of crop stage of vegetation and snow coverage. The influence of used channels and space resolution of images on the reliability and accuracy of classified areas are investigated. The improvement of interpretation is established in the case of applying the combination of unsupervised and supervised classification. The recommendations are formulated for appropriate properties of utilised space images. The diversity and amount of terrain investigations are suggested for obtaining the reliable and representative results.”

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Hydrology and Earth System Sciences

C. M. DeBeer and J. W. Pomeroy

“Simulation of areal snowmelt and snowcover depletion over time can be carried out by applying point-scale melt rate computations to distributions of snow water equivalent (SWE). In alpine basins, this can be done by considering these processes separately on individual slope units. However, differences in melt timing and rates arise at smaller spatial scales due to the variability in SWE and snowpack cold content, which affects the timing of melt initiation, depletionof the snowcover and spatial extent of the snowmelt runoff contributing area (SRCA). This study examined the effects of variability in SWE, internal energy and applied melt energy on melt rates and timing, and snowcover depletion in a small cold regions alpine basin over various scales ranging from point to basin. Melt rate computations were performed using a physically based energy balance snowmelt routine (Snobal) in the Cold Regions Hydrological Model (CRHM) and compared with measurements at 3 meteorological stations over a ridge within the basin. At the point scale, a negative association between daily melt rates and SWE was observed in the early melt period, with deeper snow requiring greater energy inputs to initiate melt. SWE distributions over the basin (stratified by slope) were measured using snow surveys and repeat LiDAR depth estimates, and used together with computed melt rates to simulate the areal snowcover depletion. Comparison with observations from georeferenced oblique photographs showed an improvement in simulated areal snowcover depletion curves when accounting for the variability in melt rate with depth of SWE in the early melt period. Finally, the SRCA was characterized as the product of the snowcovered area and the fraction of the SWE distribution undergoing active melt and producing an appreciable runoff quantity on each slope unit. Results for each slope were then aggregated to give the basin scale SRCA. The SRCA is controlled by the variability of melt amongst slope units and over individual SWE distributions, the variability of SWE, and the resulting snowcover depletion patterns over the basin.”

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Engineering Computations

Meng-Lung Lin and Cheng-Wu Chen

“Purpose – The purpose of this paper is to better understand landscape dynamics in arid and semi-arid environments. Land degradation has recently become an important issue for land management in western China. The oasis ecosystem is especially sensitive to environmental disturbances, such as abnormal/extreme precipitation events, variations in the water supply from the upper watersheds, fluctuations in temperature, etc. Satellite remote sensing of terrestrial ecosystems can provide us with the temporal dynamics and spatial distributions of green cover over large areas of landscape. Seasonal green cover data are especially important in assessing landscape health (e.g. desertification, rate of urban sprawl, natural disturbances) in arid and semi-arid regions. In this study, green cover data are derived from vegetation indices retrieved from moderate resolution imaging spectroradiometer (MODIS) sensors onboard the satellite Terra.

“Design/methodology/approach – Satellite images recorded during the period from April 2000 to December 2005 are analyzed and the spatial distribution and temporal changes of the Ejin Oasis quantified.

“Findings – This study shows that it is possible to derive important parameters linked to landscape sensitivity from MODIS and the derived imagery, such as normalized difference vegetation index (NDVI) time-series data. Such a MODIS-based time-series monitoring system is particularly useful in arid and semi-arid environments. The results of landscape sensitivity analysis prove the effectiveness of the method in assessing landscape sensitivity from the years 2001-2005.

“Practical implications – The novel strategy used in this investigation is based on the T-S fuzzy model, which is in turn based on fuzzy theory and fuzzy operations.

“Originality/value – Simulation results based on fuzzy models will help to improve the monitoring techniques used to evaluate land degradation and to estimate the newest tendency in landscape green cover dynamics in the Ejin Oasis.”

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Academic Disciplines/Professional Aspirations: Engineering/Technology; Surveying; Surveying Technology, Geographical Information Science, or Cartography.

Award: This scholarship is for use during freshman, sophomore, junior, or senior years.  This scholarship is not renewable.  Number: The number of scholarships awarded is 1.  Amount: The amount of the scholarship awarded is $1,000.

Requirements for Eligibility: The applicant is required to be enrolled or anticipating to enroll at a four-year college or university.  This scholarship is accessible only to citizens of the United States.

Requirements for Application: Application, essay composition, school transcript, resume, and personal references. Deadline: December1.

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“The National Space Policy confirms Interior’s important role in land imaging and remote sensing in coordination with NASA,” said Interior Assistant Secretary Anne Castle. “The unbiased, comprehensive data this program provides is vital to our efforts to better understand and manage land, water, and our natural resources. We look forward to working with government agencies at all levels — Federal, State, local and tribal —to promote a broad, public understanding of land and water conditions in our Nation and around the globe.”

“Land remote sensing is a crucial tool in our efforts to develop broad, effective, holistic approaches to both mitigate and adapt to the environmental challenges of our day,” said Castle, who oversees Interior’s Water and Science agencies, including the U.S. Geological Survey. “In addition, remote sensing has critical event-specific uses, for example, in closely monitoring the BP oil spill in the Gulf of Mexico and establishing baseline and post-spill conditions.”

Since 1966, Interior has managed science data operations and applications development for Landsat and other national land imaging systems from its U.S. Geological Survey Earth Resources Observation and Science Center in Sioux Falls, SD. The Department currently operates Landsats 5 and 7 and is developing the Landsat Data Continuity Mission with NASA for launch in FY 2013. The Administration is currently discussing plans for Landsat 9.

With its historical consistency, continuous global coverage, and very high quality of data, Landsat has become a vital tool worldwide for understanding scientific issues related to land use and natural resources. International applications of Landsat data have become widespread for use in agriculture, forestry, mapping, land and water assessments and climate change study.

The Department of the Interior, through the U.S. Geological Survey, facilitates access by U.S. civil agencies to national security satellite data when this data can be used for environmental assessments and disaster management. The Landsat series of satellites also is considered a cornerstone of U.S. space cooperation with foreign nations. More than 20 nations on six continents collaborate in operating local receiving stations for Landsat data on behalf of their continental regions.

On behalf of the Department, USGS publishes the entire 38-year Landsat archive over the Internet at no cost to users. In the past two years, more than 2 million current and archived images taken by Landsat have been downloaded by users throughout the world.

[U.S. Department of the Interior press release]

Earth Surface Processes and Landforms

Gareth Davies and Colin D. Woodroffe

“In order to better understand the relations between tidal estuary shape and geomorphic processes, the width profiles of 79 tidal channels from within 30 estuaries in northern Australia have been extracted from LANDSAT 5 imagery using GIS. Statistics describing the shape and width convergence of individual channels and entire estuaries (which can contain several channels) are analysed along with proxies for the tidal range and fluvial inputs of the estuaries in question. The width profiles of most individual channels can be reasonably approximated with an exponential curve, and this is also true of the width profiles of estuaries. However, the shape of this exponential width profile is strongly related to the mouth width of the system. Channels and estuaries with larger mouths generally exhibit a more pronounced funnel shape than those with narrower mouths, reflecting the hydrodynamic importance of the distance over which the channel or estuarine width converges. At the estuarine scale, this convergence length also tends to be higher in estuaries which have larger catchments relative to their size. No clear relation between the estuarine width convergence length and tidal range could be discerned within the Northern Australian estuaries although, when these data are combined with data from other studies, a weak relationship emerges.”

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